# 4AS Supersoft 5cm Microfibre Mattress Topper Double Bed

Source: https://www.ranked10.co.uk/home/best-mattress-topper/4as-supersoft-5cm
Ranked #9 in "Best Mattress Topper 2026: What 10cm Really Means": https://www.ranked10.co.uk/home/best-mattress-topper

- Price: £23.99 (checked on Amazon UK on 2026-09-11)
- Amazon rating: 4.3 from 63 ratings
- Buy on Amazon: https://www.amazon.co.uk/dp/B0GDVVMX2L?tag=ranked10-21

The 4AS is the smallest topper in this ranking at 5cm, and it makes the article's point better than anything else on the page. It weighs 1.5kg for those 5cm; the 10cm Silentnight Deep Sleep weighs 1.2kg for its claimed depth. In other words, the half-height topper carries more filling per centimetre than a best seller with eighteen thousand ratings.

So this is the choice for softening a mattress rather than rebuilding it. If your bed is simply firmer than you like and you do not want to add 7cm or 10cm of bulk, 5cm at £23.99 with elastic corner straps is the sensible amount of product.

## Specification

| Field | Value |
|---|---|
| Stated thickness | 5 cm |
| Item weight as listed | 1.5 kg |
| Price per kg of filling | £15.99 |
| Filling | 100% microfibre |
| Fixing | Elasticized corner straps |
| Care | Machine washable |

## Questions people ask

**Is 5cm enough to make a difference?**

For a mattress that is simply too firm, yes. For a dip or a sagging middle, no — that needs the 7cm memory foam toppers above.

**How does it compare with the 10cm toppers?**

It carries more filling per centimetre, 0.30kg against 0.12kg on the Silentnight Deep Sleep, and it does not add as much height to the bed.

**Will it stay in place?**

It uses elasticized corner straps, which hold the corners rather than covering the whole mattress like a fitted skirt.

**Can I wash it?**

Yes, it is machine washable microfibre.

**How many ratings does it have?**

63 at the time of collection, averaging 4.3 stars — the smallest sample in this ranking, so weigh it accordingly.

**What size is it?**

137x190cm, a UK double, for a 5cm layer.